Files
langchain/libs/partners/anthropic
Ahmed Tammaa 589bc19890 anthropic[patch]: make description optional on AnthropicTool (#30935)
PR Summary

This change adds a fallback in ChatAnthropic.with_structured_output() to
handle Pydantic models that don’t include a docstring. Without it,
calling:
```py
from pydantic import BaseModel
from langchain_anthropic import ChatAnthropic

class SampleModel(BaseModel):
    sample_field: str

llm = ChatAnthropic(
    model="claude-3-7-sonnet-latest"
).with_structured_output(SampleModel.model_json_schema())

llm.invoke("test")
```
will raise a
```
KeyError: 'description'
```
because Pydantic omits the description field when no docstring is
present.

This issue doesn’t occur when using ChatOpenAI or if you add a docstring
to the model:
```py
from pydantic import BaseModel
from langchain_openai import ChatOpenAI

class SampleModel(BaseModel):
    """Schema for sample_field output."""
    sample_field: str

llm = ChatOpenAI(
    model="gpt-4o-mini"
).with_structured_output(SampleModel.model_json_schema())

llm.invoke("test")
```

---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>
2025-04-21 10:44:39 -04:00
..
2025-04-17 14:45:12 +00:00

langchain-anthropic

This package contains the LangChain integration for Anthropic's generative models.

Installation

pip install -U langchain-anthropic

Chat Models

Anthropic recommends using their chat models over text completions.

You can see their recommended models here.

To use, you should have an Anthropic API key configured. Initialize the model as:

from langchain_anthropic import ChatAnthropic
from langchain_core.messages import AIMessage, HumanMessage

model = ChatAnthropic(model="claude-3-opus-20240229", temperature=0, max_tokens=1024)

Define the input message

message = HumanMessage(content="What is the capital of France?")

Generate a response using the model

response = model.invoke([message])

For a more detailed walkthrough see here.

LLMs (Legacy)

You can use the Claude 2 models for text completions.

from langchain_anthropic import AnthropicLLM

model = AnthropicLLM(model="claude-2.1", temperature=0, max_tokens=1024)
response = model.invoke("The best restaurant in San Francisco is: ")